Telegraph signaling system



IN VEN TOR l Her/ww' ATTORNEY Patented Mar. 9, '1926.y Y Y [UNITEDSTATES 'PATE-ur f cerros.

JOSEPH HERMAN, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONE ANDTELEGRAPH COMPANY, A CORPORATION OF NEVI YORK.

TELEGRAPH SIGNALING SYSTEM.

Application filed December?, 1923. Serial No. 669,229.

' To all whom t may conce/Mi.: Y

Be it known that I, JOSEPH HERMAN, a citizen of the Republic of Austria,residing at New York, in thecounty of New VYork .and State of New York,have invented certain Improvements in Telegraph Signaling Systems, ofwhich the following is a specifif the removal of bias from a polar relayoperating in a telegraph loop or other `open and close circuit.v I It isfrequently necessary to take tape records in atelegraph loop circuit andparv ticularly while the subscriber is sending. A polar relay .providedwith two balanced 'fwindings is generally used for this purpose. Itiswell known to those familiar with the art that-subscribers loopcircuits are op.

erated on the open and close principle, viz, when the key is closedcurrent will flow ,through the loop and operate a pole changer at theterminal office by means of which an impulse ofpredetermined polaritywill be applied to the line circuit. Upon the opening of the key at thesubscribers station current will cease to flow through theloop, and

the pole changer will thereupontransmit an Y.

impulse of opposite polarity over the line circuit. Since it isdesirable for the making of these tape records to use a polar relay, andsince the circuit'by which such rejlay is controlled operates on theopen and close principle and not upon the reversal of polarityprinciple, it becomes necessary to provide a biasing circuit for thepolar relay and to carefully adjust the magnitude of the biasing currentso that the armature of the Vrelay will be moved to one of its contactswhen current fiows through the loop ycircuit and will be moved kto itsother' contact by f virtue of the action of' the biasing winding whencurrent ceases to flow through the loop circuit. j

In order to avoid interference with the subscribers service it has beencustomary to y. adjust the relative values of the currents in the loopcircuit and inthe biasing circuit .only when the loop circuit is'idle,viz, vwhen the subscriber is not transmitting signals thereover. Themethod adopted consisted inconnecting a meter into each of the two.circuits and adjusting'the biasing circuit "the loop circuit.

until the current therein is one-half that in y Then using such method,it is lnecessary to interrupt the subscriber if the circuit is inus'evat the time or to delay the adjustment of the relay until thesubscriber stops' sending.

' It is the object of this inventionto elimi- -nate the disadvantagesinherent inl the former. practice so that full and. complete adjustmentmay be made whileH the subscriber is sending and without interferingwith the transmission ofhis signals. i j

This invention will be'clearly understood from the following descriptionwhenv read in connection with the attached drawing of which Figure lshows one form of embodiment'of the invention; Fig..2 shows amodification of the polar relay recording circuit which may beVsubstituted for the similar circuit shown in Fig. l; andFig. 3 showsschematically the arrangement of the wind? ings upon the polar relay setforth in Fig. l. In Fig. l, A representsa Morse subscriber vstationcomprising a key l, a line'relay 2 and a sounder 3, which station isconnected byv kmeans of the loop l with the pole changer 5 at theterminal station vB. The pole changer 5 has connected therewith a sourceof potential 6 from which current will iow Vthrough thel subscribersloop whenever thev key l is closed vand will operate the line relay 2`and also the said pole changer. Connected with the pole changervvis asource of potential 7 by means of which impulses of opposite polaritymay be applied through the armature of the pole changer and conductor 8to the arms'9 of the line circuit with .which are connected the line 10and the artificial line 1l'. Bridged across the arms; 9 is a polar relay12 by means of ywhich received impulses cause the operation of Athe Yreceiving apparatus which, for thesake of simplicity, is not shown.Since this invention i's. concerned with circuits that operate on theopen and close principle, of which receive the plug 14 of the monitoringrelay by means of which the tape records heretofore mentioned might bemade. It will be seen that when the plug Mis inserted in the jack 13 thecontact 15 is opened and the loop circuit is rendered continuous throughthe loop windings of the polar relay. The circuit of the monitoringrelay, normally connected with theloop circuit, comprises two windings16 and 17, preferably equal, which are adapted to be connected seriallywith the loop circuit when the arm of the switch 18 is upon the cont-actdesignated Test. The winding 17 is paralleled by a resistance 19 whichis equal to the resistance of winding 17. lVhen the arm of the switch 18is upon the contact indicated Calibrate, the winding 16 and theresistance 19 will be connected serially in the loop circuit. It isimportant vto notice that regardless ot the position of the switch' 18the resistance connected into the loop circuitreniains the same. A thirdwinding 2O"ol1 this relay is connected with the source of potential 21and a variable resistance 2 2, and these three elements constitute thebiasing circuit of this relay. Two other windings 23 and 2li areconnected in the manner shown in the drawing with a condenser 25 andresistances 2G and 27, and the circuit comprising these various elementsconstitutes the vibrating circuit of this relay. This circuit iselectrically connected with the armature 2S which is adapted to swingbetween two contacts connected with sources of potential of oppositepolarity. The armature in addition to being connected with the vibratingcircuit is connected with a polarized sounder 29'and also with arecording device 30 which may be of any well known type such as atape-recorder.

The arrangement of the windings upon I the core of the polar relay andthe connection of this relay with the operating circuit is shownschematically in Fig. 8. The invention will be apparent from thefollowing description read in connection with Figs. 1 and 3. Themonitoring relay should firstv be adjustedmechanicaily sothat itsarmature 28 will lvibrate `freely between its contacts when the biasingcircuit and the circuit' connected with the subscribers loopk are open.Assuming the armature k28 to be on its letthand contact, current williiow from its positive contact through winding 23 and resistances 26 and27 to gro-und, and a charging current will alsoiiow through winding 211,condenser 25 and resistance 27 to ground, charging the said condenser.The flow of current through winding 23V will produce a iiuX in suchdirection as to draw the armature 28 from its left-hand contact.Thereupon, the condenser 25 discharges through the circuit includingresistance 26, and windings 23 and 24, the direction of flow being suchas to produce iiuX in the same direction as that produced by currentfrom the battery through winding 23. This added impulse quickens themovement oit the armature 28 towards its right-hand contact. As soon asthe armature reaches the latter contact the negative pole of theVbatteryis connecting with the windings 23 and 24, setting up flux in anopposite direction to that created by the positive pole and causing thearmature to move back to its lett-hand contact. The armature will thusvibrate freely so long as the biasing circuit and the circuit connectedwith theV subscrihei"s loop are open. The biasing circuit is then closedand the relay is connected with the loop circuit by inserting the plug14 in the jack 13. It is desirable to point out that the currents in thebiasing circuit and in the circuit or the windings connected with theloop circuit should be in such directions that the effect produced bythe windings of therespective circuits will be opposed to each other.This is clearly shown in Fig. 3. The switch 18 is set upon the vcontactmarked Calibrate7 so that the winding 16 and the resistance 19 will beconnected with the loop'circuit while signals are transmitted over theloop by operating key 1. The resistance 22 in the biasing circuit isthen adjusted until `the armature of the relay vibrates whenever thesubscriber transmits a dash, viz, whenever he closes t-he key of hiscircuit, which vibrationl is indicated by the operation of the polarvsounder 29. lllien this condition has been attained, it will be seenthat the eiicctof the biasing winding 2O upon the armature l28 isapproximately equal and opposite to the effect oil the winding 16connected with the subscribers loop. The two eiiects thus neutralizeeach other and permit the vibrating circuit to control the action of thearmature, causing it to vibrate between contacts in the manner beforedescribed. If the switch 18 lis now movedy to the contact designatedTest, the two windings 16 and 17 will be connected serially with theloop circuit7 and while the current iiowing through the loop is the sameas it was when the switch 18 was connected with the contact markedCalibra-te, the eiiect of such current upon the armature 28, viz, theflux produced. is twice as great as before. It will accordingly be seenthat when the key 1 is open the biasing winding 20 controls the armature28 keeping it, for example, against its left-hand contact. As soon askey 1 is closed, current through windings 16 and 17 causes the armatureto move to its opposite contact. This is the condition for unbiased4operation or" the monitoring relay by the signal current in thesubscribers loop.

Fig. 2 shows a yvariation of the monitoring relay shown in Fig. 1. In'Fig. 2 there is only one winding 31 connected in series with the loopcircuit. The biasing circuit comprises a plurality of-windings 32 vand33, a(

source of potential 34, a variable resistance 35, a iiXed resistance 37,the magnitude of` which is equal to that of lthe winding 33, and aswitch 36 by means of which either the winding 33 or the resistance 37may be connected into the biasing circuit.l Thev vibrating circuit,similar to that in Figs. 1 and 3, includes the windings 38 and 39, thecondenser 40, and resistances 41 and 42.` 'The armature 43 is connectednot only with the vibrating circuit but also with the polarized sounder44 and the recording device 45.

In order to adjust the circuit shown in Fig. 2 so that the current inthe biasing circuit may be approximately one-half that which flowsthrough the winding 31, the plug 14 is inserted in the jack 13 whilesignals are being transmitted from the subscribers station A over theloop circuit. Current will accordingly flow through the winding 31 andwill act upon the armature 43 tending, for example, to hold it againstthe contact shown in the figure. Vith the arm of the switch 36 upon thecontact point marked Calibrate, the resistance 35 is varied until thecurrent flowing through the biasing circuit is sufficient to cause thearmature 43 to vibrate, which would be manifested by the operation ofthe polar sounder 44. Under this condition the effect of the currentflow through the windings 32 and 33 in series is substantially equal andopposite to the effect of the signaling current through the winding 31so that the armature is controlled by the vibrating circuit as describedin connection with Fig. 1. Since the windings 32 and 33 aresubstantially similar and equal, the effect of the biasing circuit maybe reduced one-half by cutting out the winding 33. This is done bymoving the arm of switch 36 to the test contact which connects theresistance v3'? in series with the winding 32 and the other elements ofthis circuit, and sincev the resistancev of 37 equals that of winding 33the current flow through winding 32 remains the same as before, but theeffect of the biasing circuit is only one-half as great as that ofwinding 31.

The arrangement shown in Fig. 1 is believed to be the preferable form,because the operating force upon the relay never exceeds the normaloperating force. In the ease of the circuit shown in Fig. 2, theoperating force during calibration is twice the normal value wheneverthe subscriber opens his key. This effect may prevent proper adjustmentof the relay due to the large amount of residual magnetism. Furthermore,in the case of the arrangement shown in Fig. 1, any mechanical biasingin the relay is neutralized by means of the biasing current. In the caseof Fig. 2, however, only one-half the mechanical biasing is neutralizedbecause of calibrating position to vthe test position.

Then the monitoring relay shown, for eX- ample, in Fig. 1, is properlyadjusted, the

Aarmature 28 will swing from one contact point to another as the circuitof the subscribers loop is alternately closed and opened. polarity willbe connected through the armature 28 with some form of recording deviceactuated by impulses of opposite polarity connected with the conductor30. Such recording device might beV a siphon recorder by means of whicha tape record of the sig- Vnals transmitted over the subscribers loopmight readily be obtained.

Although this invention has been disclosed as embodied in a particularform and arrangement of parts, itis not so limited but is capable ofembodiment in other and different forms within the scope of the appendedclaims.

llVhat is .claimed is:

1. In a telegraph system, the combination with a subscribers loopcircuit characterized by the opening and the closing of the circuit forthe transmission of signals, of a polarized monitoring relay connectedwith the said loop circuit having a sectionalized line winding, eachsection being substantially equal in magnitude to the other and allsections being normally eiectively in series with the said loop circuit,means for substituting for one of said sections a resistance elementequal in'magnitude to the said section, a biasing winding having asource of current and current controlling means connected in seriestherewith, and av vibrating circuit to effect the vibration of the relayarmature.

2. In a polarized relay, the combination with an operating windingconnected with a line circuit, of a biasing winding having means to varythe current therein, a vibrating circuit arranged to cause the. relayarmature to vibrate, the said operating winding being ar anged in twosubstantially equal parts normally in series, and means to effectivelydisconnect one of said parts and to substitute therefor a resistance inseries with the other-part, the said resistance being substantiallyequal in magnitude to the disconnected part of the said winding.

3. In a polarized relay,the combination l with an operating circuitcomprising two connected windings, a resistance connected with thejunction point of the said windings, switching means for effectivelyconnecting into said circuit both of said windings in series, or one ofsaid windings i-n series with the said resistance, a biasing windinghaving means to vary the current therein, the said operating winding andbiasing winding being so poled as to effect the armature of Consequentlysources of opposite',

the said relay in opposite manner, and a Vibrating circuit causing therelay :armature to vibrate between its `Contacts when the .Currents inthe operating and biasing windings substantially neutralize each other.

4e. The method of ,adjusting for proper operation u polar relay .ot thetype defined by Claim 2 connected with a circuit operating on the openyand Close principle, which consists in varying the current flow .in thebiasing winding until the eeet thereof on the armature substantiallyequal and A0ppeeite to the effect produced upon the armature by the line.current flowing` through one or' said line windings in series with :ivre- Sistanoe element of equal magnitudej then eectively 'disconnectingthe said resistance from the line circuit and substituting zmotherlinewlndlng therefor.

In .a circuit of the type defined by claim 20 v2, the method ot'adjusting the polar relay for proper operationwhieh insists in varyingthe current in the biasing winding` until it neutralizes the ,etleet ofthe current in the line winding, and detecting the Condition el 25 naineto this specification this 6th day of 30 December 1923.

JOSEPH HERMAN.

